I, and a couple of testers, felt it's worth mentioning this:
There is a level in the hack that relies on sound.

If you can't hear at all, that particular level might be an 
issue to get passed without some help. For people who can,
but have a hard time discerning sounds: I will provide a
little bit of insight for you below. Obvious spoilers ahead.

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- In Halcyon Hollow 2 - 
1: Focus on the fourth sound.
2: Focus on the third sound in the second box.
3: Focus on the fourth sound in the second box.
4: Focus on the fourth sound.

- Also, in the level Requiescence -
5: Focus on the seventh sound.